There is an increased demand for obtaining information from, and for monitoring the use, of medicament delivery devices that are handled by non-professionals, e.g. devices handled by the users themselves.
One important reason for the monitoring demands is that many physicians want to have information regarding how the patients are handling the medication based on the prescribed treatment schemes. Since many users do not meet their physicians very often, it may be difficult to have a good overview of how the patients are handling their treatments. Also, since some drugs are quite expensive, it is important that the drugs are used properly by the rightful user. Further, many drugs do not require so frequent dosing, whereby there is an increased risk that the user forgets to take the medication.
Some devices have been developed that can monitor the medicament delivery devices in order to retrieve information regarding the status of the devices. The document U.S. Pat. No. 5,536,249 discloses an injector having a microprocessor. The device is further arranged with a dose setting knob that in turn is connected to an electronic counter, which in turn is connected to the microprocessor for providing information regarding the set dose. When then a start button is activated, the microprocessor stores relevant information regarding the injection, such as the time, the date and the amount of medication injected by the user. The device then comprises a data I/O port so that information stored in the device may be uploaded to a computer, preferably at the physicist.
Document WO 2013/050535 discloses a system for determining positions of elements and in particular a plunger rod movable in a medicament delivery device. According to one embodiment a protective cap is used for measuring the positions of a plunger rod before and after administration of a dose of medicament. The positions of the plunger rod are measured by a measuring unit comprising 3D magnetrons arranged on the medicament delivery device. Further supporting electronics components including magnetic data capture are arranged in the measuring unit. Electrical connectors are arranged to transmit data from the measuring unit to the protective cap as the latter is connected to the medicament delivery device. Communication means may further be provided allowing wired or wireless transfer of data to and from a PC or a smartphone.